Conventionally various kinds of sewing methods and means have been proposed for stitching the box pockets or pipings. For example, Japanese Utility Model Kokai No. 56-9383 discloses a stitched product manufactured such that a patch cloth and a core material are retained being superimposed on a base cloth material, ends of the respective superimposed base cloth material, patch cloth and core material are stitched together to form a seam line, the patch cloth and the core material are folded along the seam line over to the opposite side of the seam line, the free end of the patch cloth is folded to the rear side of the patch cloth so as to enclose the core material, and the patch cloth thus superimposed with the rear side thereof is stitched with the patch cloth in parallel with said seam line.
Similarly, Japanese Utility Model Kokai No. 55-101580 discloses means in which a patch cloth is press supported by movable holding means upon a base cloth material placed on a sewing machine table, the base cloth/material and the patch cloth are stitched in parallel keeping a space by using two sewing needles while moving the movable holding means in a fabric feeding direction, and the base cloth material and the patch cloth between two seam lines are cut to provide a piped stitching.
As an example that teaches the similar means there can be mentioned Japanese U.M. Kokai No. 57-140268.
However, according to the piping stitching or box pocket stitching so far proposed the piping portion and its neighboring face portion of base cloth material usually vary in the number of superimposing sheets of the cloths or the like, and therefore stepped folds are created between the piping portion and its neighboring face cloth portion. Excepting a specific case such stepped folds in the piping portion have been shunned because of poor quality or undesirable finishing around a pocket. On the other hand, the piping portion with such stepped folds is likely to create a flap or creases while wearing the garment thereby presenting a problem of lowering the valuation of a suit itself.
It is therefore a first object of the present invention to overcome such a problem which occurs in stitching pipings or box pockets and to provide an improved sewing method where the piping portion and its neighboring face cloth portion are finished flat.
A second object of the present invention is to provide an apparatus for carrying out said sewing method.